drm/i915/gvt: Use common error handling code in shadow_workload_ring_buffer()

[SF Markus Elfring]

>> …  It's just that two out of three error
>> messages happened to be the same and Markus wants to save a bit of
>> memory by using the same string.  The memory savings is not so big that
>> it's worth making the code less readable.
> 
> I agree with Dan.
> 
> It doesn't save any real memory either as the compiler/linker
> reuses the repeated string.

It might depend on passing appropriate parameters.


> It might, depending on the compiler, save a few bytes of
> object code as the compiler may not optimize the repeated
> call away though.

I am trying to show corresponding change possibilities.


> But a good compiler could do that too.

Do you prefer to delegate the proposed software refactoring
only to a corresponding optimiser?

Regards,
Markus